Despite being singled out as a major cause of obesity and disease, high-fructose corn sryup (HFCS) is actually no different from table sugar, or sucrose, Lustig argues — and both are harmful. Both HFCS and sucrose are made of two bonded molecules: fructose and glucose. (However, added enzymes change the ratio of fructose and glucose in corn syrups — from 50/50 to 55/45, fructose to glucose.) Upon digestion, the body breaks down the bond, releasing glucose and fructose independently into our systems. Fructose is about twice as sweet as glucose, which explains why sugar is so much sweeter than other carbohydrate-rich foods like potatoes, which break down into glucose alone.
(More on TIME.com:Health-Washing: What's Really in Healthy Fast Food)
But given their identical component parts, why do we keep hearing that high-fructose corn syrup is so much worse for us than sugar? Lustig thinks it's simply because HFCS is ubiquitous in our food supply — it's easier to target it than regular old sugar. Corn syrup is cheap to produce, which makes is a more economical additive than refined sugar in processed foods — and, thus, it's in everything. Most people have little idea how much HFCS they actually consume in a day, because they don't know how far-reaching the ingredient is.
Next:Glucose vs. Fructose

In case you haven’t seen it yet, there’s a video on YouTube of a lecture called “Sugar: The Bitter Truth,” delivered by Dr. Robert Lustig, a pediatric endocrinologist at the University of California, San Francisco. The lecture, which runs some 90 minutes and delves into the details of the professor’s clinical observations and research, has been viewed more than a million times to date, and inspired the April 17 New York Times Magazine cover story headlined “Is Sugar Toxic?” We watched it, so you didn’t have to.